Method of improving the workability of nickel and nickel alloys



Patented May 23, 1939 METHOD OF IMPROVING THE WORKABIL- ITY OF NICKEL AND NICKEL ALLOYS Leonard of Hell, Edgbaston, Birmingham, England, usignor to The International Nickel Company, Inc., New York, N.-Y., a corporation of Delaware No Drawing. Application mm s, 1936, Serial No. 104,179. 1935 I Claims.

The present invention relates to the method of improving the workability of nickel and nickel alloys and products resulting therefrom including electric resistance units.

Nickel and its alloys have, in some cases, been somewhat difilcult to work and under certain circumstances an alkaline earth metal has often been added to the molten materials. In order to obtain the full benefits of the addition of the 10 alkaline earth, it is desirable to add more of the alkaline earth metal, calcium for example, than is consumed by the desired chemical reactions.. This results in a residue of calcium or other alkaline earth in the finished material (or a residue of some other element reduced from the furnace lining, slag, and so forth, by the excess calcium, etc.), but it is important to control theamount of alkaline earth metal that is-left as the presence of more than a certain amount of calcium or other alkaline earth metal makes the material I unworkable.

I have made the surprising discovery that the necessity for strict control of the amount of calcium or other alkaline earth metal can be avoided and yet the materials can be rendered easily workable.

' It is an object of'the present invention to provide a method of improving the workability of nickel and/or nickel alloys. l

It is another object of the present invention to provide means for obviating the need for ex- .treme care in ,regulating the initial amount of. alkaline earth metal added to nickel and/or nickel alloys. f

It is a further object of the present invention to compensate for theexcess oi. alkaline earth present in a nickel and/or nickel alloy material by the addition of a regulated, critical amount of another element usually considered deleterious. 40 The present invention also contemplates the production of nickel alloys particularly suitable for use as electrical resistance units.

Other objects and advantages will become apparent from the following description.

In general, the present inyentioncontemplates melting nickel and/or nickel alloying metals in the usual manner followed by the usual deoxi'dising, desulfurislng, etc. The deoxidising, desulfu'rising, etc., may be'carried out by the addition 50 of calcium silicide or other alkaline earth metals or alkaline earth metal alloys,-"or' by means of aluminum, cerium and related elements (including thorium, hafnium, scandium, yttrium, and zirconium); and manganese, molybdenum, sili- 55 con and titanium may be added with advantage.

.be carried out in any s itable manner.

In Great Britain October 15,

Other elements that may be added are barium,

beryllium, boron, cobalt, copper, lithium, magthan one such metal is left in the finished material, and similarly more than one of the metals usually considered deleterious may be added.

It is convenient to describe the nature of the present invention in connection with calcium and arsenic, but it is to be understood that these may bium, and tantalum.

mony, phosphorus, bismuth, vanadium, colum- The amount of calcium and the accompanying arsenic to be added to the melt varies according to the working conditions, i. e. the type of furnace,conditions of the lining, the speed of melting, the nature of the raw materials, and other similar factors, but in order to give an indication of the relative amounts of calcium and arsenic, it may be stated that when between about 0.05 and about 0.15% calcium is present in the finished material this may advantageously be accompanied by about 0.01 to about 0.05% arsenic. In general, it is preferred so to carry on the process that small quantities of calcium and an element of Group V remain in the finished mate rial because in this way, .it can be ensured that the beneficial effects obtained by their addition to the molten material are produced to the full. The preferred ranges are as follows:

Percent by Percent by Element weight Element weight Phosphorus-.." 0. 01 to 0. Arsenic 0.01 to 0. Antimony 0. 01 to 0. Vanadium 0:01 to'OI Oolumblnm or niobfumufl, 0. (ll f0 0. 75 Tantalum 010110 0. 25

In the case of bismuth, not more than 0.075%, should be added.

.As is well known, the'calcium may be added as a metal-or as an alloy or compound, such as calcium silicide and the Group V element may be "added in the elemental form or as an alloy or compound, such as, for example, nickel arsenide or calcium phosphide. The alloying process may Thus, a preliminary addition of calcium silicide may be made to the melt and any substantial excess of calcium removed by oxidation. A final calcium I silicide addition may be made just before casting. The less oxidizable of the Group V elements may be added at any stage in the melting process, or may be added in a suitable alloyed form withthe cold charge, but with those elements of the Group V with a high aflinity for oxygen, hat is to say, vanadium, niobium or columbium and tantalum, it is preferred to add the element after the main part of the charge has been melted and subjected to a preliminary, deoxidation treatment.

The additions may be made by plunging the elements or alloys to the bottom of the molten metal by any suitable means so as to improve the alloying process. The Group V elements together with part or all the calcium, or other alkaline earth metal, may, however, be added to the molten stream during the pouring of the metal.

For the 'purpose of giving those skilled in the art a better understanding of the present invention, the following examples-are given by way of illustration.

Example No. 1

In the production of the well-known 00/20 nickel-chromium alloy according to the present ample, be followed:

About 800 pounds of nickel are melted and subjected to deoxidation by the addition of about 0.25 to about 0.5% manganese and about 0.25% silicon, about 200 pounds of chromium are added and when the massis molten about 6 pounds of calcium silicide containing about 25% calcium are added. This is equivalent to adding about 0.13% calcium to the melt. When sufilcient time has been allowed for the desired reactions to proceed and the temperature of the metal has been adjusted to that correct for casting, the metal is poured into a ladle, and about 0.5 of a pound of metallic arsenic is added thereto. About 1 pound of calcium silicide is introduced into the ladle, and the metal is cast. These last addi- I t ions represent about 0.045% and about 0.08%,

respectively, of the total mass.

Example No. 2

The procedure of Example No. 1 is followed until the chromium has been addedto the melt, and then about 4 pounds of the calcium silicide and, for example, about 1 pound of commercial cerium areadded. The melt is poured into the ladle while adding about 0.25 pound of metallic arsenic, About 0.50 pound of calcium silicide andv about 1 pound of cerium are added while the metal is in the ladle.

Example N0. 3

As illustrative of the process according to the present invention as applied to the production of nickel, the following example is given I About 1000 pounds of commercial nickel are melted together. with about 0.25% manganese and about 0.1% silicon. When molten, the metal is poured into the ladle and during the pouring operation, anaddition of about 0.025% arsenic is made followed by about 0.05% calcium either form or in the form of calcium silicide. I

In the application of the present invention to the preparation of iron-nickel alloys the following example is presented for illustrative purposes:-

Example No. 4 Inthe production of a 50-5o nickel-iron alloy,

about 500 .of nickel and about 500 pounds of iron are melted together with about 0.25% manganese and about 0.1% silicon. when molten, the metal is poured into the ladle and during the pouring operation an addition of about 0.025% arsenic is made followed by the addition of about 0.05% calcium either in the metallic form or in the form of calcium silicide.

The present invention may be applied with particular advantage to those nickel-chromium and nickel-chromium-iron alloys from which,

bodiments, it is to be understood that variations and modifications may be made by those skilled in the art. Such variations and modifications are considered to be within the spirit and scop of the appended claims.

It is to be understood that the.term deoxidation, as used herein, includes such preliminary treatment as deoxidizing, desulfurising, etc.

1 claim:

1. The process of manufacturing nickelable amount of nickel, deoxidizing the nickel by the addition of a deoxidizer, adding a suitable amount of chromium, allowing the materials to become molten, adding a suitable amount of chromium alloys which comprises melting a suitcalcium silicide containing about 25% calcium,-

allowing suiiicient time to elapse for the desired reactions to proceed,- adjusting the temperature of the metal to that correct for casting,

pouring the metal into a ladle, adding a suitable amount of arsenic to the streamof molten metal, introducing further amounts of calcium silicide into the'ladle and casting the metal containing small amounts of calcium and arsenic whereby the workability of the finished material is improved.

2. The process of manufacturing nickelchromium alloys which comprises melting about 800 pounds of nickel, deoxidizing said nickel by metallic arsenic to thestream' of molten metal,

introducing about 1 pound of calcium silicide into the ladleand casting the metal whereby nickel chromium alloys are obtained having improved workability and containing small amounts of calcium and arsenic. 3. The process of manufacturing nickelchromium alloys which comprises meltinga charge of nickel, deoxidizing said nickel, adding a suitable amount of chromium, allowing the mass to become molten, adding a quantity of calcium equivalent to about 0.13% of the mass, allowing sumcient time to elapse for the desired reactions to proceed, adjusting the temperature to that cor rect for casting, pouring the metal into a ladle,

adding a quantity of arsenic equivalent to about 0.045 oi the mass to the stream of molten metal, adding a quantity of calcium silicide equivalent to about 0.09% oi the mass to the metal in the ladle and casting the metal whereby nickel-chromium alloys are obtained having improved workability and containing small amounts of calcium and arsenic.

4. The process of counteracting the deleterious eflect of excess amount of calcium on the workability oi nickel alloys containing about 80% nickel and about chromium which comprises subjecting a molten mass of said nickel alloys to deoxidation treatment; subsequently treating said molten mass with about 0.01% to about 0.15% calcium and incorporating in said molten mass restricted and controlled amounts of arsenic within the range oi about 0.01% to about 0.2% and solidifying the thus-treated metal whereby sound, solid nickel alloys containing about nickel and about 20% chromium are produced having improved workabilityand being devoid oi the 'deleterious effect of an exces amount of calcium.

5. The process of counteracting the deleterious eiiect of excess amount of calcium on the workability of nickel-chromium alloys which comprises subjecting a molten mass oi nickel-chromium alloy to deoxidation treatment; subsequently treating said molten mass with about 0.01% to about 0.15% oi calcium and incorporating in said molten mass restricted and controlled amounts oi arsenic within the range oi about 0.01% to about 0.2%: and solidifying the thus-treated metal whereby sound, solid nickel-chromium alloys are produced having improved workability and being devoid of the deleterious eflect of an excess amountoi calcium,

6. The process oi counteracting the deleterious eiiect oi excess amount oi alkaline earth metal on the properties of nickel-chromium alloys which comprises subjecting a molten mass oi nickelchromium alloy to deoxidation treatment, subsequently treating said molten mass with about 0.01% to about 0.2% oi alkaline earth metal and incorporating in said molten mass at least one element 'i'rom the group consisting oi arsenic, antimony andphosphorus in restricted and controlled amounts within the range oi about 0.01% to about 0.2%, about 0.01% to about 0.25%, and about 0.01% to about 0.06%. respectively; and'solidiir ing the thus-treated metal whereby sound solid nickel-chromium alloys are produced having in proved'properties and being devoid oi the deleterious eii'ect oi an excess amount oi alkaline 7. The process oi counteracting the deleterious eiiect oi excess amount oi calcium on the workability oi nickel and nickel alloys which comprises subjecting a molten nickel massyto deosidation treatment; subsequently treating said molten mass with about 0.01% to about 0.15% calcium and incorporating in said molten mass restricted and controlled amounts of arsenic within the range oi about 0.01% to about 0.2%; and solidifying the thus-treated metal whereby sound, solid nickel and nickel alloys are produced having improved workability and being devoid of the dele-. terious eiiect of an excess amount of calcium.

8. The process of counteracting the deleterious eiiect oi excess amount oi alkaline earth metal on the properties of nickel and nickel alloys which comprises deoxidizing a molten nickel mass;

treating said molten mass with about 0.01% to about 0.20% of alkaline earth metal and incorporating in said molten mass restricted and controlled amounts of at least one element from the group consisting of arsenic, antimony and phos-' phorus within the range of about 0.01% to about 0.25%; and solidifying the thus-treated metal whereby sound, solid nickel and nickel alloys are produced having improved properties and being devoid or the deleterious effect of an excess amount of alkaline earth metal.

9. The process of counteracting the deleterious eflect of excess amount of alkaline earth metal on the properties of nickel and nickel alloys and of avoiding the necessity for strict control of the amount oi alkaline earth metal in nickel and nickel alloys which comprises deoxidizing a molten nickel mass; subsequently treating said molten mass with about 0.01% to about 0.2% of alkaline earth metal and incorporating in said molten. mass at least one element irom the group consisting oi arsenic, antimony and phosphorus in restricted and controlled amounts within the range of about 0.01% to about 0.2%, about 0.01%

controlled amounts within the range oi about 0.01% to about 0.2%; and solidiiying the thustreated metal whereby sound, solid nickel'is produced having improved workability and being devoid oi the deleterious eiiect oi an excess amount oi calcium. 

